devmode: make reusable

the `devmode` helper made for the Nixpkgs/NixOS manual was exposed wrapped
in `mkShell`, which made it impossible to reuse.

this change strips that wrapper and reproduces it at the call site.

now one can use `devmode` from anywhere Nixpkgs is available:

    devmode = pkgs.callPackage "${pkgs.path}/pkgs/tools/nix/web-devmode.nix" {
      buildArgs = toString ./.;
      open = "/index.html";
    };

0 files changed, 0 insertions, 0 deletions